<!DOCTYPE html>
<html>
<head>
  <script src="https://cdn.rawgit.com/konvajs/konva/1.4.0/konva.min.js"></script>
  <meta charset="utf-8">
  <title>Konva Rect Demo</title>
    <style>
        body {
            margin: 0;
            padding: 0;
            overflow: hidden;
            background-color: #F0F0F0;
        }
    </style>
</head>
<body>
  <div id="container"></div>
  <script>
    var width = window.innerWidth;
    var height = window.innerHeight;

    var stage = new Konva.Stage({
      container: 'container',
      width: width,
      height: height
    });

    var layer = new Konva.Layer();

    var rect = new Konva.Rect({
      x: 50,
      y: 50,
      width: 100,
      height: 50,
      fill: 'green',
      stroke: 'black',
      strokeWidth: 4
    });

    // add the shape to the layer
    layer.add(rect);

    // add the layer to the stage
    stage.add(layer);
  </script>

</body>
</html>